xref: /openbmc/linux/net/ipv4/igmp.c (revision 96ac6d43)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
4  *
5  *	This code implements the IGMP protocol as defined in RFC1112. There has
6  *	been a further revision of this protocol since which is now supported.
7  *
8  *	If you have trouble with this module be careful what gcc you have used,
9  *	the older version didn't come out right using gcc 2.5.8, the newer one
10  *	seems to fall out with gcc 2.6.2.
11  *
12  *	Authors:
13  *		Alan Cox <alan@lxorguk.ukuu.org.uk>
14  *
15  *	Fixes:
16  *
17  *		Alan Cox	:	Added lots of __inline__ to optimise
18  *					the memory usage of all the tiny little
19  *					functions.
20  *		Alan Cox	:	Dumped the header building experiment.
21  *		Alan Cox	:	Minor tweaks ready for multicast routing
22  *					and extended IGMP protocol.
23  *		Alan Cox	:	Removed a load of inline directives. Gcc 2.5.8
24  *					writes utterly bogus code otherwise (sigh)
25  *					fixed IGMP loopback to behave in the manner
26  *					desired by mrouted, fixed the fact it has been
27  *					broken since 1.3.6 and cleaned up a few minor
28  *					points.
29  *
30  *		Chih-Jen Chang	:	Tried to revise IGMP to Version 2
31  *		Tsu-Sheng Tsao		E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
32  *					The enhancements are mainly based on Steve Deering's
33  * 					ipmulti-3.5 source code.
34  *		Chih-Jen Chang	:	Added the igmp_get_mrouter_info and
35  *		Tsu-Sheng Tsao		igmp_set_mrouter_info to keep track of
36  *					the mrouted version on that device.
37  *		Chih-Jen Chang	:	Added the max_resp_time parameter to
38  *		Tsu-Sheng Tsao		igmp_heard_query(). Using this parameter
39  *					to identify the multicast router version
40  *					and do what the IGMP version 2 specified.
41  *		Chih-Jen Chang	:	Added a timer to revert to IGMP V2 router
42  *		Tsu-Sheng Tsao		if the specified time expired.
43  *		Alan Cox	:	Stop IGMP from 0.0.0.0 being accepted.
44  *		Alan Cox	:	Use GFP_ATOMIC in the right places.
45  *		Christian Daudt :	igmp timer wasn't set for local group
46  *					memberships but was being deleted,
47  *					which caused a "del_timer() called
48  *					from %p with timer not initialized\n"
49  *					message (960131).
50  *		Christian Daudt :	removed del_timer from
51  *					igmp_timer_expire function (960205).
52  *             Christian Daudt :       igmp_heard_report now only calls
53  *                                     igmp_timer_expire if tm->running is
54  *                                     true (960216).
55  *		Malcolm Beattie :	ttl comparison wrong in igmp_rcv made
56  *					igmp_heard_query never trigger. Expiry
57  *					miscalculation fixed in igmp_heard_query
58  *					and random() made to return unsigned to
59  *					prevent negative expiry times.
60  *		Alexey Kuznetsov:	Wrong group leaving behaviour, backport
61  *					fix from pending 2.1.x patches.
62  *		Alan Cox:		Forget to enable FDDI support earlier.
63  *		Alexey Kuznetsov:	Fixed leaving groups on device down.
64  *		Alexey Kuznetsov:	Accordance to igmp-v2-06 draft.
65  *		David L Stevens:	IGMPv3 support, with help from
66  *					Vinay Kulkarni
67  */
68 
69 #include <linux/module.h>
70 #include <linux/slab.h>
71 #include <linux/uaccess.h>
72 #include <linux/types.h>
73 #include <linux/kernel.h>
74 #include <linux/jiffies.h>
75 #include <linux/string.h>
76 #include <linux/socket.h>
77 #include <linux/sockios.h>
78 #include <linux/in.h>
79 #include <linux/inet.h>
80 #include <linux/netdevice.h>
81 #include <linux/skbuff.h>
82 #include <linux/inetdevice.h>
83 #include <linux/igmp.h>
84 #include <linux/if_arp.h>
85 #include <linux/rtnetlink.h>
86 #include <linux/times.h>
87 #include <linux/pkt_sched.h>
88 #include <linux/byteorder/generic.h>
89 
90 #include <net/net_namespace.h>
91 #include <net/arp.h>
92 #include <net/ip.h>
93 #include <net/protocol.h>
94 #include <net/route.h>
95 #include <net/sock.h>
96 #include <net/checksum.h>
97 #include <net/inet_common.h>
98 #include <linux/netfilter_ipv4.h>
99 #ifdef CONFIG_IP_MROUTE
100 #include <linux/mroute.h>
101 #endif
102 #ifdef CONFIG_PROC_FS
103 #include <linux/proc_fs.h>
104 #include <linux/seq_file.h>
105 #endif
106 
107 #ifdef CONFIG_IP_MULTICAST
108 /* Parameter names and values are taken from igmp-v2-06 draft */
109 
110 #define IGMP_V2_UNSOLICITED_REPORT_INTERVAL	(10*HZ)
111 #define IGMP_V3_UNSOLICITED_REPORT_INTERVAL	(1*HZ)
112 #define IGMP_QUERY_INTERVAL			(125*HZ)
113 #define IGMP_QUERY_RESPONSE_INTERVAL		(10*HZ)
114 
115 #define IGMP_INITIAL_REPORT_DELAY		(1)
116 
117 /* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
118  * IGMP specs require to report membership immediately after
119  * joining a group, but we delay the first report by a
120  * small interval. It seems more natural and still does not
121  * contradict to specs provided this delay is small enough.
122  */
123 
124 #define IGMP_V1_SEEN(in_dev) \
125 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
126 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
127 	 ((in_dev)->mr_v1_seen && \
128 	  time_before(jiffies, (in_dev)->mr_v1_seen)))
129 #define IGMP_V2_SEEN(in_dev) \
130 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
131 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
132 	 ((in_dev)->mr_v2_seen && \
133 	  time_before(jiffies, (in_dev)->mr_v2_seen)))
134 
135 static int unsolicited_report_interval(struct in_device *in_dev)
136 {
137 	int interval_ms, interval_jiffies;
138 
139 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
140 		interval_ms = IN_DEV_CONF_GET(
141 			in_dev,
142 			IGMPV2_UNSOLICITED_REPORT_INTERVAL);
143 	else /* v3 */
144 		interval_ms = IN_DEV_CONF_GET(
145 			in_dev,
146 			IGMPV3_UNSOLICITED_REPORT_INTERVAL);
147 
148 	interval_jiffies = msecs_to_jiffies(interval_ms);
149 
150 	/* _timer functions can't handle a delay of 0 jiffies so ensure
151 	 *  we always return a positive value.
152 	 */
153 	if (interval_jiffies <= 0)
154 		interval_jiffies = 1;
155 	return interval_jiffies;
156 }
157 
158 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
159 			      gfp_t gfp);
160 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
161 static void igmpv3_clear_delrec(struct in_device *in_dev);
162 static int sf_setstate(struct ip_mc_list *pmc);
163 static void sf_markstate(struct ip_mc_list *pmc);
164 #endif
165 static void ip_mc_clear_src(struct ip_mc_list *pmc);
166 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
167 			 int sfcount, __be32 *psfsrc, int delta);
168 
169 static void ip_ma_put(struct ip_mc_list *im)
170 {
171 	if (refcount_dec_and_test(&im->refcnt)) {
172 		in_dev_put(im->interface);
173 		kfree_rcu(im, rcu);
174 	}
175 }
176 
177 #define for_each_pmc_rcu(in_dev, pmc)				\
178 	for (pmc = rcu_dereference(in_dev->mc_list);		\
179 	     pmc != NULL;					\
180 	     pmc = rcu_dereference(pmc->next_rcu))
181 
182 #define for_each_pmc_rtnl(in_dev, pmc)				\
183 	for (pmc = rtnl_dereference(in_dev->mc_list);		\
184 	     pmc != NULL;					\
185 	     pmc = rtnl_dereference(pmc->next_rcu))
186 
187 #ifdef CONFIG_IP_MULTICAST
188 
189 /*
190  *	Timer management
191  */
192 
193 static void igmp_stop_timer(struct ip_mc_list *im)
194 {
195 	spin_lock_bh(&im->lock);
196 	if (del_timer(&im->timer))
197 		refcount_dec(&im->refcnt);
198 	im->tm_running = 0;
199 	im->reporter = 0;
200 	im->unsolicit_count = 0;
201 	spin_unlock_bh(&im->lock);
202 }
203 
204 /* It must be called with locked im->lock */
205 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
206 {
207 	int tv = prandom_u32() % max_delay;
208 
209 	im->tm_running = 1;
210 	if (!mod_timer(&im->timer, jiffies+tv+2))
211 		refcount_inc(&im->refcnt);
212 }
213 
214 static void igmp_gq_start_timer(struct in_device *in_dev)
215 {
216 	int tv = prandom_u32() % in_dev->mr_maxdelay;
217 	unsigned long exp = jiffies + tv + 2;
218 
219 	if (in_dev->mr_gq_running &&
220 	    time_after_eq(exp, (in_dev->mr_gq_timer).expires))
221 		return;
222 
223 	in_dev->mr_gq_running = 1;
224 	if (!mod_timer(&in_dev->mr_gq_timer, exp))
225 		in_dev_hold(in_dev);
226 }
227 
228 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
229 {
230 	int tv = prandom_u32() % delay;
231 
232 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
233 		in_dev_hold(in_dev);
234 }
235 
236 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
237 {
238 	spin_lock_bh(&im->lock);
239 	im->unsolicit_count = 0;
240 	if (del_timer(&im->timer)) {
241 		if ((long)(im->timer.expires-jiffies) < max_delay) {
242 			add_timer(&im->timer);
243 			im->tm_running = 1;
244 			spin_unlock_bh(&im->lock);
245 			return;
246 		}
247 		refcount_dec(&im->refcnt);
248 	}
249 	igmp_start_timer(im, max_delay);
250 	spin_unlock_bh(&im->lock);
251 }
252 
253 
254 /*
255  *	Send an IGMP report.
256  */
257 
258 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
259 
260 
261 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
262 	int gdeleted, int sdeleted)
263 {
264 	switch (type) {
265 	case IGMPV3_MODE_IS_INCLUDE:
266 	case IGMPV3_MODE_IS_EXCLUDE:
267 		if (gdeleted || sdeleted)
268 			return 0;
269 		if (!(pmc->gsquery && !psf->sf_gsresp)) {
270 			if (pmc->sfmode == MCAST_INCLUDE)
271 				return 1;
272 			/* don't include if this source is excluded
273 			 * in all filters
274 			 */
275 			if (psf->sf_count[MCAST_INCLUDE])
276 				return type == IGMPV3_MODE_IS_INCLUDE;
277 			return pmc->sfcount[MCAST_EXCLUDE] ==
278 				psf->sf_count[MCAST_EXCLUDE];
279 		}
280 		return 0;
281 	case IGMPV3_CHANGE_TO_INCLUDE:
282 		if (gdeleted || sdeleted)
283 			return 0;
284 		return psf->sf_count[MCAST_INCLUDE] != 0;
285 	case IGMPV3_CHANGE_TO_EXCLUDE:
286 		if (gdeleted || sdeleted)
287 			return 0;
288 		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
289 		    psf->sf_count[MCAST_INCLUDE])
290 			return 0;
291 		return pmc->sfcount[MCAST_EXCLUDE] ==
292 			psf->sf_count[MCAST_EXCLUDE];
293 	case IGMPV3_ALLOW_NEW_SOURCES:
294 		if (gdeleted || !psf->sf_crcount)
295 			return 0;
296 		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
297 	case IGMPV3_BLOCK_OLD_SOURCES:
298 		if (pmc->sfmode == MCAST_INCLUDE)
299 			return gdeleted || (psf->sf_crcount && sdeleted);
300 		return psf->sf_crcount && !gdeleted && !sdeleted;
301 	}
302 	return 0;
303 }
304 
305 static int
306 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
307 {
308 	struct ip_sf_list *psf;
309 	int scount = 0;
310 
311 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
312 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
313 			continue;
314 		scount++;
315 	}
316 	return scount;
317 }
318 
319 /* source address selection per RFC 3376 section 4.2.13 */
320 static __be32 igmpv3_get_srcaddr(struct net_device *dev,
321 				 const struct flowi4 *fl4)
322 {
323 	struct in_device *in_dev = __in_dev_get_rcu(dev);
324 
325 	if (!in_dev)
326 		return htonl(INADDR_ANY);
327 
328 	for_ifa(in_dev) {
329 		if (fl4->saddr == ifa->ifa_local)
330 			return fl4->saddr;
331 	} endfor_ifa(in_dev);
332 
333 	return htonl(INADDR_ANY);
334 }
335 
336 static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
337 {
338 	struct sk_buff *skb;
339 	struct rtable *rt;
340 	struct iphdr *pip;
341 	struct igmpv3_report *pig;
342 	struct net *net = dev_net(dev);
343 	struct flowi4 fl4;
344 	int hlen = LL_RESERVED_SPACE(dev);
345 	int tlen = dev->needed_tailroom;
346 	unsigned int size = mtu;
347 
348 	while (1) {
349 		skb = alloc_skb(size + hlen + tlen,
350 				GFP_ATOMIC | __GFP_NOWARN);
351 		if (skb)
352 			break;
353 		size >>= 1;
354 		if (size < 256)
355 			return NULL;
356 	}
357 	skb->priority = TC_PRIO_CONTROL;
358 
359 	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
360 				   0, 0,
361 				   IPPROTO_IGMP, 0, dev->ifindex);
362 	if (IS_ERR(rt)) {
363 		kfree_skb(skb);
364 		return NULL;
365 	}
366 
367 	skb_dst_set(skb, &rt->dst);
368 	skb->dev = dev;
369 
370 	skb_reserve(skb, hlen);
371 	skb_tailroom_reserve(skb, mtu, tlen);
372 
373 	skb_reset_network_header(skb);
374 	pip = ip_hdr(skb);
375 	skb_put(skb, sizeof(struct iphdr) + 4);
376 
377 	pip->version  = 4;
378 	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
379 	pip->tos      = 0xc0;
380 	pip->frag_off = htons(IP_DF);
381 	pip->ttl      = 1;
382 	pip->daddr    = fl4.daddr;
383 
384 	rcu_read_lock();
385 	pip->saddr    = igmpv3_get_srcaddr(dev, &fl4);
386 	rcu_read_unlock();
387 
388 	pip->protocol = IPPROTO_IGMP;
389 	pip->tot_len  = 0;	/* filled in later */
390 	ip_select_ident(net, skb, NULL);
391 	((u8 *)&pip[1])[0] = IPOPT_RA;
392 	((u8 *)&pip[1])[1] = 4;
393 	((u8 *)&pip[1])[2] = 0;
394 	((u8 *)&pip[1])[3] = 0;
395 
396 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
397 	skb_put(skb, sizeof(*pig));
398 	pig = igmpv3_report_hdr(skb);
399 	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
400 	pig->resv1 = 0;
401 	pig->csum = 0;
402 	pig->resv2 = 0;
403 	pig->ngrec = 0;
404 	return skb;
405 }
406 
407 static int igmpv3_sendpack(struct sk_buff *skb)
408 {
409 	struct igmphdr *pig = igmp_hdr(skb);
410 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
411 
412 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
413 
414 	return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
415 }
416 
417 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
418 {
419 	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
420 }
421 
422 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
423 	int type, struct igmpv3_grec **ppgr, unsigned int mtu)
424 {
425 	struct net_device *dev = pmc->interface->dev;
426 	struct igmpv3_report *pih;
427 	struct igmpv3_grec *pgr;
428 
429 	if (!skb) {
430 		skb = igmpv3_newpack(dev, mtu);
431 		if (!skb)
432 			return NULL;
433 	}
434 	pgr = skb_put(skb, sizeof(struct igmpv3_grec));
435 	pgr->grec_type = type;
436 	pgr->grec_auxwords = 0;
437 	pgr->grec_nsrcs = 0;
438 	pgr->grec_mca = pmc->multiaddr;
439 	pih = igmpv3_report_hdr(skb);
440 	pih->ngrec = htons(ntohs(pih->ngrec)+1);
441 	*ppgr = pgr;
442 	return skb;
443 }
444 
445 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
446 
447 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
448 	int type, int gdeleted, int sdeleted)
449 {
450 	struct net_device *dev = pmc->interface->dev;
451 	struct net *net = dev_net(dev);
452 	struct igmpv3_report *pih;
453 	struct igmpv3_grec *pgr = NULL;
454 	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
455 	int scount, stotal, first, isquery, truncate;
456 	unsigned int mtu;
457 
458 	if (pmc->multiaddr == IGMP_ALL_HOSTS)
459 		return skb;
460 	if (ipv4_is_local_multicast(pmc->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
461 		return skb;
462 
463 	mtu = READ_ONCE(dev->mtu);
464 	if (mtu < IPV4_MIN_MTU)
465 		return skb;
466 
467 	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
468 		  type == IGMPV3_MODE_IS_EXCLUDE;
469 	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
470 		    type == IGMPV3_CHANGE_TO_EXCLUDE;
471 
472 	stotal = scount = 0;
473 
474 	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
475 
476 	if (!*psf_list)
477 		goto empty_source;
478 
479 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
480 
481 	/* EX and TO_EX get a fresh packet, if needed */
482 	if (truncate) {
483 		if (pih && pih->ngrec &&
484 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
485 			if (skb)
486 				igmpv3_sendpack(skb);
487 			skb = igmpv3_newpack(dev, mtu);
488 		}
489 	}
490 	first = 1;
491 	psf_prev = NULL;
492 	for (psf = *psf_list; psf; psf = psf_next) {
493 		__be32 *psrc;
494 
495 		psf_next = psf->sf_next;
496 
497 		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
498 			psf_prev = psf;
499 			continue;
500 		}
501 
502 		/* Based on RFC3376 5.1. Should not send source-list change
503 		 * records when there is a filter mode change.
504 		 */
505 		if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||
506 		     (!gdeleted && pmc->crcount)) &&
507 		    (type == IGMPV3_ALLOW_NEW_SOURCES ||
508 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)
509 			goto decrease_sf_crcount;
510 
511 		/* clear marks on query responses */
512 		if (isquery)
513 			psf->sf_gsresp = 0;
514 
515 		if (AVAILABLE(skb) < sizeof(__be32) +
516 		    first*sizeof(struct igmpv3_grec)) {
517 			if (truncate && !first)
518 				break;	 /* truncate these */
519 			if (pgr)
520 				pgr->grec_nsrcs = htons(scount);
521 			if (skb)
522 				igmpv3_sendpack(skb);
523 			skb = igmpv3_newpack(dev, mtu);
524 			first = 1;
525 			scount = 0;
526 		}
527 		if (first) {
528 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
529 			first = 0;
530 		}
531 		if (!skb)
532 			return NULL;
533 		psrc = skb_put(skb, sizeof(__be32));
534 		*psrc = psf->sf_inaddr;
535 		scount++; stotal++;
536 		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
537 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
538 decrease_sf_crcount:
539 			psf->sf_crcount--;
540 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
541 				if (psf_prev)
542 					psf_prev->sf_next = psf->sf_next;
543 				else
544 					*psf_list = psf->sf_next;
545 				kfree(psf);
546 				continue;
547 			}
548 		}
549 		psf_prev = psf;
550 	}
551 
552 empty_source:
553 	if (!stotal) {
554 		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
555 		    type == IGMPV3_BLOCK_OLD_SOURCES)
556 			return skb;
557 		if (pmc->crcount || isquery) {
558 			/* make sure we have room for group header */
559 			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
560 				igmpv3_sendpack(skb);
561 				skb = NULL; /* add_grhead will get a new one */
562 			}
563 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
564 		}
565 	}
566 	if (pgr)
567 		pgr->grec_nsrcs = htons(scount);
568 
569 	if (isquery)
570 		pmc->gsquery = 0;	/* clear query state on report */
571 	return skb;
572 }
573 
574 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
575 {
576 	struct sk_buff *skb = NULL;
577 	struct net *net = dev_net(in_dev->dev);
578 	int type;
579 
580 	if (!pmc) {
581 		rcu_read_lock();
582 		for_each_pmc_rcu(in_dev, pmc) {
583 			if (pmc->multiaddr == IGMP_ALL_HOSTS)
584 				continue;
585 			if (ipv4_is_local_multicast(pmc->multiaddr) &&
586 			     !net->ipv4.sysctl_igmp_llm_reports)
587 				continue;
588 			spin_lock_bh(&pmc->lock);
589 			if (pmc->sfcount[MCAST_EXCLUDE])
590 				type = IGMPV3_MODE_IS_EXCLUDE;
591 			else
592 				type = IGMPV3_MODE_IS_INCLUDE;
593 			skb = add_grec(skb, pmc, type, 0, 0);
594 			spin_unlock_bh(&pmc->lock);
595 		}
596 		rcu_read_unlock();
597 	} else {
598 		spin_lock_bh(&pmc->lock);
599 		if (pmc->sfcount[MCAST_EXCLUDE])
600 			type = IGMPV3_MODE_IS_EXCLUDE;
601 		else
602 			type = IGMPV3_MODE_IS_INCLUDE;
603 		skb = add_grec(skb, pmc, type, 0, 0);
604 		spin_unlock_bh(&pmc->lock);
605 	}
606 	if (!skb)
607 		return 0;
608 	return igmpv3_sendpack(skb);
609 }
610 
611 /*
612  * remove zero-count source records from a source filter list
613  */
614 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
615 {
616 	struct ip_sf_list *psf_prev, *psf_next, *psf;
617 
618 	psf_prev = NULL;
619 	for (psf = *ppsf; psf; psf = psf_next) {
620 		psf_next = psf->sf_next;
621 		if (psf->sf_crcount == 0) {
622 			if (psf_prev)
623 				psf_prev->sf_next = psf->sf_next;
624 			else
625 				*ppsf = psf->sf_next;
626 			kfree(psf);
627 		} else
628 			psf_prev = psf;
629 	}
630 }
631 
632 static void igmpv3_send_cr(struct in_device *in_dev)
633 {
634 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
635 	struct sk_buff *skb = NULL;
636 	int type, dtype;
637 
638 	rcu_read_lock();
639 	spin_lock_bh(&in_dev->mc_tomb_lock);
640 
641 	/* deleted MCA's */
642 	pmc_prev = NULL;
643 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
644 		pmc_next = pmc->next;
645 		if (pmc->sfmode == MCAST_INCLUDE) {
646 			type = IGMPV3_BLOCK_OLD_SOURCES;
647 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
648 			skb = add_grec(skb, pmc, type, 1, 0);
649 			skb = add_grec(skb, pmc, dtype, 1, 1);
650 		}
651 		if (pmc->crcount) {
652 			if (pmc->sfmode == MCAST_EXCLUDE) {
653 				type = IGMPV3_CHANGE_TO_INCLUDE;
654 				skb = add_grec(skb, pmc, type, 1, 0);
655 			}
656 			pmc->crcount--;
657 			if (pmc->crcount == 0) {
658 				igmpv3_clear_zeros(&pmc->tomb);
659 				igmpv3_clear_zeros(&pmc->sources);
660 			}
661 		}
662 		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
663 			if (pmc_prev)
664 				pmc_prev->next = pmc_next;
665 			else
666 				in_dev->mc_tomb = pmc_next;
667 			in_dev_put(pmc->interface);
668 			kfree(pmc);
669 		} else
670 			pmc_prev = pmc;
671 	}
672 	spin_unlock_bh(&in_dev->mc_tomb_lock);
673 
674 	/* change recs */
675 	for_each_pmc_rcu(in_dev, pmc) {
676 		spin_lock_bh(&pmc->lock);
677 		if (pmc->sfcount[MCAST_EXCLUDE]) {
678 			type = IGMPV3_BLOCK_OLD_SOURCES;
679 			dtype = IGMPV3_ALLOW_NEW_SOURCES;
680 		} else {
681 			type = IGMPV3_ALLOW_NEW_SOURCES;
682 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
683 		}
684 		skb = add_grec(skb, pmc, type, 0, 0);
685 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
686 
687 		/* filter mode changes */
688 		if (pmc->crcount) {
689 			if (pmc->sfmode == MCAST_EXCLUDE)
690 				type = IGMPV3_CHANGE_TO_EXCLUDE;
691 			else
692 				type = IGMPV3_CHANGE_TO_INCLUDE;
693 			skb = add_grec(skb, pmc, type, 0, 0);
694 			pmc->crcount--;
695 		}
696 		spin_unlock_bh(&pmc->lock);
697 	}
698 	rcu_read_unlock();
699 
700 	if (!skb)
701 		return;
702 	(void) igmpv3_sendpack(skb);
703 }
704 
705 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
706 	int type)
707 {
708 	struct sk_buff *skb;
709 	struct iphdr *iph;
710 	struct igmphdr *ih;
711 	struct rtable *rt;
712 	struct net_device *dev = in_dev->dev;
713 	struct net *net = dev_net(dev);
714 	__be32	group = pmc ? pmc->multiaddr : 0;
715 	struct flowi4 fl4;
716 	__be32	dst;
717 	int hlen, tlen;
718 
719 	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
720 		return igmpv3_send_report(in_dev, pmc);
721 
722 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
723 		return 0;
724 
725 	if (type == IGMP_HOST_LEAVE_MESSAGE)
726 		dst = IGMP_ALL_ROUTER;
727 	else
728 		dst = group;
729 
730 	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
731 				   0, 0,
732 				   IPPROTO_IGMP, 0, dev->ifindex);
733 	if (IS_ERR(rt))
734 		return -1;
735 
736 	hlen = LL_RESERVED_SPACE(dev);
737 	tlen = dev->needed_tailroom;
738 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
739 	if (!skb) {
740 		ip_rt_put(rt);
741 		return -1;
742 	}
743 	skb->priority = TC_PRIO_CONTROL;
744 
745 	skb_dst_set(skb, &rt->dst);
746 
747 	skb_reserve(skb, hlen);
748 
749 	skb_reset_network_header(skb);
750 	iph = ip_hdr(skb);
751 	skb_put(skb, sizeof(struct iphdr) + 4);
752 
753 	iph->version  = 4;
754 	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
755 	iph->tos      = 0xc0;
756 	iph->frag_off = htons(IP_DF);
757 	iph->ttl      = 1;
758 	iph->daddr    = dst;
759 	iph->saddr    = fl4.saddr;
760 	iph->protocol = IPPROTO_IGMP;
761 	ip_select_ident(net, skb, NULL);
762 	((u8 *)&iph[1])[0] = IPOPT_RA;
763 	((u8 *)&iph[1])[1] = 4;
764 	((u8 *)&iph[1])[2] = 0;
765 	((u8 *)&iph[1])[3] = 0;
766 
767 	ih = skb_put(skb, sizeof(struct igmphdr));
768 	ih->type = type;
769 	ih->code = 0;
770 	ih->csum = 0;
771 	ih->group = group;
772 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
773 
774 	return ip_local_out(net, skb->sk, skb);
775 }
776 
777 static void igmp_gq_timer_expire(struct timer_list *t)
778 {
779 	struct in_device *in_dev = from_timer(in_dev, t, mr_gq_timer);
780 
781 	in_dev->mr_gq_running = 0;
782 	igmpv3_send_report(in_dev, NULL);
783 	in_dev_put(in_dev);
784 }
785 
786 static void igmp_ifc_timer_expire(struct timer_list *t)
787 {
788 	struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer);
789 
790 	igmpv3_send_cr(in_dev);
791 	if (in_dev->mr_ifc_count) {
792 		in_dev->mr_ifc_count--;
793 		igmp_ifc_start_timer(in_dev,
794 				     unsolicited_report_interval(in_dev));
795 	}
796 	in_dev_put(in_dev);
797 }
798 
799 static void igmp_ifc_event(struct in_device *in_dev)
800 {
801 	struct net *net = dev_net(in_dev->dev);
802 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
803 		return;
804 	in_dev->mr_ifc_count = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
805 	igmp_ifc_start_timer(in_dev, 1);
806 }
807 
808 
809 static void igmp_timer_expire(struct timer_list *t)
810 {
811 	struct ip_mc_list *im = from_timer(im, t, timer);
812 	struct in_device *in_dev = im->interface;
813 
814 	spin_lock(&im->lock);
815 	im->tm_running = 0;
816 
817 	if (im->unsolicit_count && --im->unsolicit_count)
818 		igmp_start_timer(im, unsolicited_report_interval(in_dev));
819 
820 	im->reporter = 1;
821 	spin_unlock(&im->lock);
822 
823 	if (IGMP_V1_SEEN(in_dev))
824 		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
825 	else if (IGMP_V2_SEEN(in_dev))
826 		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
827 	else
828 		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
829 
830 	ip_ma_put(im);
831 }
832 
833 /* mark EXCLUDE-mode sources */
834 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
835 {
836 	struct ip_sf_list *psf;
837 	int i, scount;
838 
839 	scount = 0;
840 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
841 		if (scount == nsrcs)
842 			break;
843 		for (i = 0; i < nsrcs; i++) {
844 			/* skip inactive filters */
845 			if (psf->sf_count[MCAST_INCLUDE] ||
846 			    pmc->sfcount[MCAST_EXCLUDE] !=
847 			    psf->sf_count[MCAST_EXCLUDE])
848 				break;
849 			if (srcs[i] == psf->sf_inaddr) {
850 				scount++;
851 				break;
852 			}
853 		}
854 	}
855 	pmc->gsquery = 0;
856 	if (scount == nsrcs)	/* all sources excluded */
857 		return 0;
858 	return 1;
859 }
860 
861 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
862 {
863 	struct ip_sf_list *psf;
864 	int i, scount;
865 
866 	if (pmc->sfmode == MCAST_EXCLUDE)
867 		return igmp_xmarksources(pmc, nsrcs, srcs);
868 
869 	/* mark INCLUDE-mode sources */
870 	scount = 0;
871 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
872 		if (scount == nsrcs)
873 			break;
874 		for (i = 0; i < nsrcs; i++)
875 			if (srcs[i] == psf->sf_inaddr) {
876 				psf->sf_gsresp = 1;
877 				scount++;
878 				break;
879 			}
880 	}
881 	if (!scount) {
882 		pmc->gsquery = 0;
883 		return 0;
884 	}
885 	pmc->gsquery = 1;
886 	return 1;
887 }
888 
889 /* return true if packet was dropped */
890 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
891 {
892 	struct ip_mc_list *im;
893 	struct net *net = dev_net(in_dev->dev);
894 
895 	/* Timers are only set for non-local groups */
896 
897 	if (group == IGMP_ALL_HOSTS)
898 		return false;
899 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
900 		return false;
901 
902 	rcu_read_lock();
903 	for_each_pmc_rcu(in_dev, im) {
904 		if (im->multiaddr == group) {
905 			igmp_stop_timer(im);
906 			break;
907 		}
908 	}
909 	rcu_read_unlock();
910 	return false;
911 }
912 
913 /* return true if packet was dropped */
914 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
915 	int len)
916 {
917 	struct igmphdr 		*ih = igmp_hdr(skb);
918 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
919 	struct ip_mc_list	*im;
920 	__be32			group = ih->group;
921 	int			max_delay;
922 	int			mark = 0;
923 	struct net		*net = dev_net(in_dev->dev);
924 
925 
926 	if (len == 8) {
927 		if (ih->code == 0) {
928 			/* Alas, old v1 router presents here. */
929 
930 			max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
931 			in_dev->mr_v1_seen = jiffies +
932 				(in_dev->mr_qrv * in_dev->mr_qi) +
933 				in_dev->mr_qri;
934 			group = 0;
935 		} else {
936 			/* v2 router present */
937 			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
938 			in_dev->mr_v2_seen = jiffies +
939 				(in_dev->mr_qrv * in_dev->mr_qi) +
940 				in_dev->mr_qri;
941 		}
942 		/* cancel the interface change timer */
943 		in_dev->mr_ifc_count = 0;
944 		if (del_timer(&in_dev->mr_ifc_timer))
945 			__in_dev_put(in_dev);
946 		/* clear deleted report items */
947 		igmpv3_clear_delrec(in_dev);
948 	} else if (len < 12) {
949 		return true;	/* ignore bogus packet; freed by caller */
950 	} else if (IGMP_V1_SEEN(in_dev)) {
951 		/* This is a v3 query with v1 queriers present */
952 		max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
953 		group = 0;
954 	} else if (IGMP_V2_SEEN(in_dev)) {
955 		/* this is a v3 query with v2 queriers present;
956 		 * Interpretation of the max_delay code is problematic here.
957 		 * A real v2 host would use ih_code directly, while v3 has a
958 		 * different encoding. We use the v3 encoding as more likely
959 		 * to be intended in a v3 query.
960 		 */
961 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
962 		if (!max_delay)
963 			max_delay = 1;	/* can't mod w/ 0 */
964 	} else { /* v3 */
965 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
966 			return true;
967 
968 		ih3 = igmpv3_query_hdr(skb);
969 		if (ih3->nsrcs) {
970 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
971 					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
972 				return true;
973 			ih3 = igmpv3_query_hdr(skb);
974 		}
975 
976 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
977 		if (!max_delay)
978 			max_delay = 1;	/* can't mod w/ 0 */
979 		in_dev->mr_maxdelay = max_delay;
980 
981 		/* RFC3376, 4.1.6. QRV and 4.1.7. QQIC, when the most recently
982 		 * received value was zero, use the default or statically
983 		 * configured value.
984 		 */
985 		in_dev->mr_qrv = ih3->qrv ?: net->ipv4.sysctl_igmp_qrv;
986 		in_dev->mr_qi = IGMPV3_QQIC(ih3->qqic)*HZ ?: IGMP_QUERY_INTERVAL;
987 
988 		/* RFC3376, 8.3. Query Response Interval:
989 		 * The number of seconds represented by the [Query Response
990 		 * Interval] must be less than the [Query Interval].
991 		 */
992 		if (in_dev->mr_qri >= in_dev->mr_qi)
993 			in_dev->mr_qri = (in_dev->mr_qi/HZ - 1)*HZ;
994 
995 		if (!group) { /* general query */
996 			if (ih3->nsrcs)
997 				return true;	/* no sources allowed */
998 			igmp_gq_start_timer(in_dev);
999 			return false;
1000 		}
1001 		/* mark sources to include, if group & source-specific */
1002 		mark = ih3->nsrcs != 0;
1003 	}
1004 
1005 	/*
1006 	 * - Start the timers in all of our membership records
1007 	 *   that the query applies to for the interface on
1008 	 *   which the query arrived excl. those that belong
1009 	 *   to a "local" group (224.0.0.X)
1010 	 * - For timers already running check if they need to
1011 	 *   be reset.
1012 	 * - Use the igmp->igmp_code field as the maximum
1013 	 *   delay possible
1014 	 */
1015 	rcu_read_lock();
1016 	for_each_pmc_rcu(in_dev, im) {
1017 		int changed;
1018 
1019 		if (group && group != im->multiaddr)
1020 			continue;
1021 		if (im->multiaddr == IGMP_ALL_HOSTS)
1022 			continue;
1023 		if (ipv4_is_local_multicast(im->multiaddr) &&
1024 		    !net->ipv4.sysctl_igmp_llm_reports)
1025 			continue;
1026 		spin_lock_bh(&im->lock);
1027 		if (im->tm_running)
1028 			im->gsquery = im->gsquery && mark;
1029 		else
1030 			im->gsquery = mark;
1031 		changed = !im->gsquery ||
1032 			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
1033 		spin_unlock_bh(&im->lock);
1034 		if (changed)
1035 			igmp_mod_timer(im, max_delay);
1036 	}
1037 	rcu_read_unlock();
1038 	return false;
1039 }
1040 
1041 /* called in rcu_read_lock() section */
1042 int igmp_rcv(struct sk_buff *skb)
1043 {
1044 	/* This basically follows the spec line by line -- see RFC1112 */
1045 	struct igmphdr *ih;
1046 	struct net_device *dev = skb->dev;
1047 	struct in_device *in_dev;
1048 	int len = skb->len;
1049 	bool dropped = true;
1050 
1051 	if (netif_is_l3_master(dev)) {
1052 		dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
1053 		if (!dev)
1054 			goto drop;
1055 	}
1056 
1057 	in_dev = __in_dev_get_rcu(dev);
1058 	if (!in_dev)
1059 		goto drop;
1060 
1061 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
1062 		goto drop;
1063 
1064 	if (skb_checksum_simple_validate(skb))
1065 		goto drop;
1066 
1067 	ih = igmp_hdr(skb);
1068 	switch (ih->type) {
1069 	case IGMP_HOST_MEMBERSHIP_QUERY:
1070 		dropped = igmp_heard_query(in_dev, skb, len);
1071 		break;
1072 	case IGMP_HOST_MEMBERSHIP_REPORT:
1073 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1074 		/* Is it our report looped back? */
1075 		if (rt_is_output_route(skb_rtable(skb)))
1076 			break;
1077 		/* don't rely on MC router hearing unicast reports */
1078 		if (skb->pkt_type == PACKET_MULTICAST ||
1079 		    skb->pkt_type == PACKET_BROADCAST)
1080 			dropped = igmp_heard_report(in_dev, ih->group);
1081 		break;
1082 	case IGMP_PIM:
1083 #ifdef CONFIG_IP_PIMSM_V1
1084 		return pim_rcv_v1(skb);
1085 #endif
1086 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1087 	case IGMP_DVMRP:
1088 	case IGMP_TRACE:
1089 	case IGMP_HOST_LEAVE_MESSAGE:
1090 	case IGMP_MTRACE:
1091 	case IGMP_MTRACE_RESP:
1092 		break;
1093 	default:
1094 		break;
1095 	}
1096 
1097 drop:
1098 	if (dropped)
1099 		kfree_skb(skb);
1100 	else
1101 		consume_skb(skb);
1102 	return 0;
1103 }
1104 
1105 #endif
1106 
1107 
1108 /*
1109  *	Add a filter to a device
1110  */
1111 
1112 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1113 {
1114 	char buf[MAX_ADDR_LEN];
1115 	struct net_device *dev = in_dev->dev;
1116 
1117 	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1118 	   We will get multicast token leakage, when IFF_MULTICAST
1119 	   is changed. This check should be done in ndo_set_rx_mode
1120 	   routine. Something sort of:
1121 	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1122 	   --ANK
1123 	   */
1124 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1125 		dev_mc_add(dev, buf);
1126 }
1127 
1128 /*
1129  *	Remove a filter from a device
1130  */
1131 
1132 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1133 {
1134 	char buf[MAX_ADDR_LEN];
1135 	struct net_device *dev = in_dev->dev;
1136 
1137 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1138 		dev_mc_del(dev, buf);
1139 }
1140 
1141 #ifdef CONFIG_IP_MULTICAST
1142 /*
1143  * deleted ip_mc_list manipulation
1144  */
1145 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
1146 			      gfp_t gfp)
1147 {
1148 	struct ip_mc_list *pmc;
1149 	struct net *net = dev_net(in_dev->dev);
1150 
1151 	/* this is an "ip_mc_list" for convenience; only the fields below
1152 	 * are actually used. In particular, the refcnt and users are not
1153 	 * used for management of the delete list. Using the same structure
1154 	 * for deleted items allows change reports to use common code with
1155 	 * non-deleted or query-response MCA's.
1156 	 */
1157 	pmc = kzalloc(sizeof(*pmc), gfp);
1158 	if (!pmc)
1159 		return;
1160 	spin_lock_init(&pmc->lock);
1161 	spin_lock_bh(&im->lock);
1162 	pmc->interface = im->interface;
1163 	in_dev_hold(in_dev);
1164 	pmc->multiaddr = im->multiaddr;
1165 	pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1166 	pmc->sfmode = im->sfmode;
1167 	if (pmc->sfmode == MCAST_INCLUDE) {
1168 		struct ip_sf_list *psf;
1169 
1170 		pmc->tomb = im->tomb;
1171 		pmc->sources = im->sources;
1172 		im->tomb = im->sources = NULL;
1173 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1174 			psf->sf_crcount = pmc->crcount;
1175 	}
1176 	spin_unlock_bh(&im->lock);
1177 
1178 	spin_lock_bh(&in_dev->mc_tomb_lock);
1179 	pmc->next = in_dev->mc_tomb;
1180 	in_dev->mc_tomb = pmc;
1181 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1182 }
1183 
1184 /*
1185  * restore ip_mc_list deleted records
1186  */
1187 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1188 {
1189 	struct ip_mc_list *pmc, *pmc_prev;
1190 	struct ip_sf_list *psf;
1191 	struct net *net = dev_net(in_dev->dev);
1192 	__be32 multiaddr = im->multiaddr;
1193 
1194 	spin_lock_bh(&in_dev->mc_tomb_lock);
1195 	pmc_prev = NULL;
1196 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
1197 		if (pmc->multiaddr == multiaddr)
1198 			break;
1199 		pmc_prev = pmc;
1200 	}
1201 	if (pmc) {
1202 		if (pmc_prev)
1203 			pmc_prev->next = pmc->next;
1204 		else
1205 			in_dev->mc_tomb = pmc->next;
1206 	}
1207 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1208 
1209 	spin_lock_bh(&im->lock);
1210 	if (pmc) {
1211 		im->interface = pmc->interface;
1212 		if (im->sfmode == MCAST_INCLUDE) {
1213 			im->tomb = pmc->tomb;
1214 			im->sources = pmc->sources;
1215 			for (psf = im->sources; psf; psf = psf->sf_next)
1216 				psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1217 		} else {
1218 			im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1219 		}
1220 		in_dev_put(pmc->interface);
1221 		kfree(pmc);
1222 	}
1223 	spin_unlock_bh(&im->lock);
1224 }
1225 
1226 /*
1227  * flush ip_mc_list deleted records
1228  */
1229 static void igmpv3_clear_delrec(struct in_device *in_dev)
1230 {
1231 	struct ip_mc_list *pmc, *nextpmc;
1232 
1233 	spin_lock_bh(&in_dev->mc_tomb_lock);
1234 	pmc = in_dev->mc_tomb;
1235 	in_dev->mc_tomb = NULL;
1236 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1237 
1238 	for (; pmc; pmc = nextpmc) {
1239 		nextpmc = pmc->next;
1240 		ip_mc_clear_src(pmc);
1241 		in_dev_put(pmc->interface);
1242 		kfree(pmc);
1243 	}
1244 	/* clear dead sources, too */
1245 	rcu_read_lock();
1246 	for_each_pmc_rcu(in_dev, pmc) {
1247 		struct ip_sf_list *psf, *psf_next;
1248 
1249 		spin_lock_bh(&pmc->lock);
1250 		psf = pmc->tomb;
1251 		pmc->tomb = NULL;
1252 		spin_unlock_bh(&pmc->lock);
1253 		for (; psf; psf = psf_next) {
1254 			psf_next = psf->sf_next;
1255 			kfree(psf);
1256 		}
1257 	}
1258 	rcu_read_unlock();
1259 }
1260 #endif
1261 
1262 static void __igmp_group_dropped(struct ip_mc_list *im, gfp_t gfp)
1263 {
1264 	struct in_device *in_dev = im->interface;
1265 #ifdef CONFIG_IP_MULTICAST
1266 	struct net *net = dev_net(in_dev->dev);
1267 	int reporter;
1268 #endif
1269 
1270 	if (im->loaded) {
1271 		im->loaded = 0;
1272 		ip_mc_filter_del(in_dev, im->multiaddr);
1273 	}
1274 
1275 #ifdef CONFIG_IP_MULTICAST
1276 	if (im->multiaddr == IGMP_ALL_HOSTS)
1277 		return;
1278 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1279 		return;
1280 
1281 	reporter = im->reporter;
1282 	igmp_stop_timer(im);
1283 
1284 	if (!in_dev->dead) {
1285 		if (IGMP_V1_SEEN(in_dev))
1286 			return;
1287 		if (IGMP_V2_SEEN(in_dev)) {
1288 			if (reporter)
1289 				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1290 			return;
1291 		}
1292 		/* IGMPv3 */
1293 		igmpv3_add_delrec(in_dev, im, gfp);
1294 
1295 		igmp_ifc_event(in_dev);
1296 	}
1297 #endif
1298 }
1299 
1300 static void igmp_group_dropped(struct ip_mc_list *im)
1301 {
1302 	__igmp_group_dropped(im, GFP_KERNEL);
1303 }
1304 
1305 static void igmp_group_added(struct ip_mc_list *im)
1306 {
1307 	struct in_device *in_dev = im->interface;
1308 #ifdef CONFIG_IP_MULTICAST
1309 	struct net *net = dev_net(in_dev->dev);
1310 #endif
1311 
1312 	if (im->loaded == 0) {
1313 		im->loaded = 1;
1314 		ip_mc_filter_add(in_dev, im->multiaddr);
1315 	}
1316 
1317 #ifdef CONFIG_IP_MULTICAST
1318 	if (im->multiaddr == IGMP_ALL_HOSTS)
1319 		return;
1320 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1321 		return;
1322 
1323 	if (in_dev->dead)
1324 		return;
1325 
1326 	im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
1327 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1328 		spin_lock_bh(&im->lock);
1329 		igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
1330 		spin_unlock_bh(&im->lock);
1331 		return;
1332 	}
1333 	/* else, v3 */
1334 
1335 	/* Based on RFC3376 5.1, for newly added INCLUDE SSM, we should
1336 	 * not send filter-mode change record as the mode should be from
1337 	 * IN() to IN(A).
1338 	 */
1339 	if (im->sfmode == MCAST_EXCLUDE)
1340 		im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1341 
1342 	igmp_ifc_event(in_dev);
1343 #endif
1344 }
1345 
1346 
1347 /*
1348  *	Multicast list managers
1349  */
1350 
1351 static u32 ip_mc_hash(const struct ip_mc_list *im)
1352 {
1353 	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1354 }
1355 
1356 static void ip_mc_hash_add(struct in_device *in_dev,
1357 			   struct ip_mc_list *im)
1358 {
1359 	struct ip_mc_list __rcu **mc_hash;
1360 	u32 hash;
1361 
1362 	mc_hash = rtnl_dereference(in_dev->mc_hash);
1363 	if (mc_hash) {
1364 		hash = ip_mc_hash(im);
1365 		im->next_hash = mc_hash[hash];
1366 		rcu_assign_pointer(mc_hash[hash], im);
1367 		return;
1368 	}
1369 
1370 	/* do not use a hash table for small number of items */
1371 	if (in_dev->mc_count < 4)
1372 		return;
1373 
1374 	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1375 			  GFP_KERNEL);
1376 	if (!mc_hash)
1377 		return;
1378 
1379 	for_each_pmc_rtnl(in_dev, im) {
1380 		hash = ip_mc_hash(im);
1381 		im->next_hash = mc_hash[hash];
1382 		RCU_INIT_POINTER(mc_hash[hash], im);
1383 	}
1384 
1385 	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1386 }
1387 
1388 static void ip_mc_hash_remove(struct in_device *in_dev,
1389 			      struct ip_mc_list *im)
1390 {
1391 	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1392 	struct ip_mc_list *aux;
1393 
1394 	if (!mc_hash)
1395 		return;
1396 	mc_hash += ip_mc_hash(im);
1397 	while ((aux = rtnl_dereference(*mc_hash)) != im)
1398 		mc_hash = &aux->next_hash;
1399 	*mc_hash = im->next_hash;
1400 }
1401 
1402 
1403 /*
1404  *	A socket has joined a multicast group on device dev.
1405  */
1406 static void ____ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
1407 				unsigned int mode, gfp_t gfp)
1408 {
1409 	struct ip_mc_list *im;
1410 
1411 	ASSERT_RTNL();
1412 
1413 	for_each_pmc_rtnl(in_dev, im) {
1414 		if (im->multiaddr == addr) {
1415 			im->users++;
1416 			ip_mc_add_src(in_dev, &addr, mode, 0, NULL, 0);
1417 			goto out;
1418 		}
1419 	}
1420 
1421 	im = kzalloc(sizeof(*im), gfp);
1422 	if (!im)
1423 		goto out;
1424 
1425 	im->users = 1;
1426 	im->interface = in_dev;
1427 	in_dev_hold(in_dev);
1428 	im->multiaddr = addr;
1429 	/* initial mode is (EX, empty) */
1430 	im->sfmode = mode;
1431 	im->sfcount[mode] = 1;
1432 	refcount_set(&im->refcnt, 1);
1433 	spin_lock_init(&im->lock);
1434 #ifdef CONFIG_IP_MULTICAST
1435 	timer_setup(&im->timer, igmp_timer_expire, 0);
1436 #endif
1437 
1438 	im->next_rcu = in_dev->mc_list;
1439 	in_dev->mc_count++;
1440 	rcu_assign_pointer(in_dev->mc_list, im);
1441 
1442 	ip_mc_hash_add(in_dev, im);
1443 
1444 #ifdef CONFIG_IP_MULTICAST
1445 	igmpv3_del_delrec(in_dev, im);
1446 #endif
1447 	igmp_group_added(im);
1448 	if (!in_dev->dead)
1449 		ip_rt_multicast_event(in_dev);
1450 out:
1451 	return;
1452 }
1453 
1454 void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
1455 {
1456 	____ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE, gfp);
1457 }
1458 EXPORT_SYMBOL(__ip_mc_inc_group);
1459 
1460 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1461 {
1462 	__ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE);
1463 }
1464 EXPORT_SYMBOL(ip_mc_inc_group);
1465 
1466 static int ip_mc_check_iphdr(struct sk_buff *skb)
1467 {
1468 	const struct iphdr *iph;
1469 	unsigned int len;
1470 	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1471 
1472 	if (!pskb_may_pull(skb, offset))
1473 		return -EINVAL;
1474 
1475 	iph = ip_hdr(skb);
1476 
1477 	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1478 		return -EINVAL;
1479 
1480 	offset += ip_hdrlen(skb) - sizeof(*iph);
1481 
1482 	if (!pskb_may_pull(skb, offset))
1483 		return -EINVAL;
1484 
1485 	iph = ip_hdr(skb);
1486 
1487 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1488 		return -EINVAL;
1489 
1490 	len = skb_network_offset(skb) + ntohs(iph->tot_len);
1491 	if (skb->len < len || len < offset)
1492 		return -EINVAL;
1493 
1494 	skb_set_transport_header(skb, offset);
1495 
1496 	return 0;
1497 }
1498 
1499 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1500 {
1501 	unsigned int len = skb_transport_offset(skb);
1502 
1503 	len += sizeof(struct igmpv3_report);
1504 
1505 	return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
1506 }
1507 
1508 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1509 {
1510 	unsigned int transport_len = ip_transport_len(skb);
1511 	unsigned int len;
1512 
1513 	/* IGMPv{1,2}? */
1514 	if (transport_len != sizeof(struct igmphdr)) {
1515 		/* or IGMPv3? */
1516 		if (transport_len < sizeof(struct igmpv3_query))
1517 			return -EINVAL;
1518 
1519 		len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
1520 		if (!ip_mc_may_pull(skb, len))
1521 			return -EINVAL;
1522 	}
1523 
1524 	/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
1525 	 * all-systems destination addresses (224.0.0.1) for general queries
1526 	 */
1527 	if (!igmp_hdr(skb)->group &&
1528 	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1529 		return -EINVAL;
1530 
1531 	return 0;
1532 }
1533 
1534 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1535 {
1536 	switch (igmp_hdr(skb)->type) {
1537 	case IGMP_HOST_LEAVE_MESSAGE:
1538 	case IGMP_HOST_MEMBERSHIP_REPORT:
1539 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1540 		return 0;
1541 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1542 		return ip_mc_check_igmp_reportv3(skb);
1543 	case IGMP_HOST_MEMBERSHIP_QUERY:
1544 		return ip_mc_check_igmp_query(skb);
1545 	default:
1546 		return -ENOMSG;
1547 	}
1548 }
1549 
1550 static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1551 {
1552 	return skb_checksum_simple_validate(skb);
1553 }
1554 
1555 static int ip_mc_check_igmp_csum(struct sk_buff *skb)
1556 {
1557 	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1558 	unsigned int transport_len = ip_transport_len(skb);
1559 	struct sk_buff *skb_chk;
1560 
1561 	if (!ip_mc_may_pull(skb, len))
1562 		return -EINVAL;
1563 
1564 	skb_chk = skb_checksum_trimmed(skb, transport_len,
1565 				       ip_mc_validate_checksum);
1566 	if (!skb_chk)
1567 		return -EINVAL;
1568 
1569 	if (skb_chk != skb)
1570 		kfree_skb(skb_chk);
1571 
1572 	return 0;
1573 }
1574 
1575 /**
1576  * ip_mc_check_igmp - checks whether this is a sane IGMP packet
1577  * @skb: the skb to validate
1578  *
1579  * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
1580  * skb transport header accordingly and returns zero.
1581  *
1582  * -EINVAL: A broken packet was detected, i.e. it violates some internet
1583  *  standard
1584  * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
1585  * -ENOMEM: A memory allocation failure happened.
1586  *
1587  * Caller needs to set the skb network header and free any returned skb if it
1588  * differs from the provided skb.
1589  */
1590 int ip_mc_check_igmp(struct sk_buff *skb)
1591 {
1592 	int ret = ip_mc_check_iphdr(skb);
1593 
1594 	if (ret < 0)
1595 		return ret;
1596 
1597 	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1598 		return -ENOMSG;
1599 
1600 	ret = ip_mc_check_igmp_csum(skb);
1601 	if (ret < 0)
1602 		return ret;
1603 
1604 	return ip_mc_check_igmp_msg(skb);
1605 }
1606 EXPORT_SYMBOL(ip_mc_check_igmp);
1607 
1608 /*
1609  *	Resend IGMP JOIN report; used by netdev notifier.
1610  */
1611 static void ip_mc_rejoin_groups(struct in_device *in_dev)
1612 {
1613 #ifdef CONFIG_IP_MULTICAST
1614 	struct ip_mc_list *im;
1615 	int type;
1616 	struct net *net = dev_net(in_dev->dev);
1617 
1618 	ASSERT_RTNL();
1619 
1620 	for_each_pmc_rtnl(in_dev, im) {
1621 		if (im->multiaddr == IGMP_ALL_HOSTS)
1622 			continue;
1623 		if (ipv4_is_local_multicast(im->multiaddr) &&
1624 		    !net->ipv4.sysctl_igmp_llm_reports)
1625 			continue;
1626 
1627 		/* a failover is happening and switches
1628 		 * must be notified immediately
1629 		 */
1630 		if (IGMP_V1_SEEN(in_dev))
1631 			type = IGMP_HOST_MEMBERSHIP_REPORT;
1632 		else if (IGMP_V2_SEEN(in_dev))
1633 			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1634 		else
1635 			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1636 		igmp_send_report(in_dev, im, type);
1637 	}
1638 #endif
1639 }
1640 
1641 /*
1642  *	A socket has left a multicast group on device dev
1643  */
1644 
1645 void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
1646 {
1647 	struct ip_mc_list *i;
1648 	struct ip_mc_list __rcu **ip;
1649 
1650 	ASSERT_RTNL();
1651 
1652 	for (ip = &in_dev->mc_list;
1653 	     (i = rtnl_dereference(*ip)) != NULL;
1654 	     ip = &i->next_rcu) {
1655 		if (i->multiaddr == addr) {
1656 			if (--i->users == 0) {
1657 				ip_mc_hash_remove(in_dev, i);
1658 				*ip = i->next_rcu;
1659 				in_dev->mc_count--;
1660 				__igmp_group_dropped(i, gfp);
1661 				ip_mc_clear_src(i);
1662 
1663 				if (!in_dev->dead)
1664 					ip_rt_multicast_event(in_dev);
1665 
1666 				ip_ma_put(i);
1667 				return;
1668 			}
1669 			break;
1670 		}
1671 	}
1672 }
1673 EXPORT_SYMBOL(__ip_mc_dec_group);
1674 
1675 /* Device changing type */
1676 
1677 void ip_mc_unmap(struct in_device *in_dev)
1678 {
1679 	struct ip_mc_list *pmc;
1680 
1681 	ASSERT_RTNL();
1682 
1683 	for_each_pmc_rtnl(in_dev, pmc)
1684 		igmp_group_dropped(pmc);
1685 }
1686 
1687 void ip_mc_remap(struct in_device *in_dev)
1688 {
1689 	struct ip_mc_list *pmc;
1690 
1691 	ASSERT_RTNL();
1692 
1693 	for_each_pmc_rtnl(in_dev, pmc) {
1694 #ifdef CONFIG_IP_MULTICAST
1695 		igmpv3_del_delrec(in_dev, pmc);
1696 #endif
1697 		igmp_group_added(pmc);
1698 	}
1699 }
1700 
1701 /* Device going down */
1702 
1703 void ip_mc_down(struct in_device *in_dev)
1704 {
1705 	struct ip_mc_list *pmc;
1706 
1707 	ASSERT_RTNL();
1708 
1709 	for_each_pmc_rtnl(in_dev, pmc)
1710 		igmp_group_dropped(pmc);
1711 
1712 #ifdef CONFIG_IP_MULTICAST
1713 	in_dev->mr_ifc_count = 0;
1714 	if (del_timer(&in_dev->mr_ifc_timer))
1715 		__in_dev_put(in_dev);
1716 	in_dev->mr_gq_running = 0;
1717 	if (del_timer(&in_dev->mr_gq_timer))
1718 		__in_dev_put(in_dev);
1719 #endif
1720 
1721 	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1722 }
1723 
1724 #ifdef CONFIG_IP_MULTICAST
1725 static void ip_mc_reset(struct in_device *in_dev)
1726 {
1727 	struct net *net = dev_net(in_dev->dev);
1728 
1729 	in_dev->mr_qi = IGMP_QUERY_INTERVAL;
1730 	in_dev->mr_qri = IGMP_QUERY_RESPONSE_INTERVAL;
1731 	in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1732 }
1733 #else
1734 static void ip_mc_reset(struct in_device *in_dev)
1735 {
1736 }
1737 #endif
1738 
1739 void ip_mc_init_dev(struct in_device *in_dev)
1740 {
1741 	ASSERT_RTNL();
1742 
1743 #ifdef CONFIG_IP_MULTICAST
1744 	timer_setup(&in_dev->mr_gq_timer, igmp_gq_timer_expire, 0);
1745 	timer_setup(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire, 0);
1746 #endif
1747 	ip_mc_reset(in_dev);
1748 
1749 	spin_lock_init(&in_dev->mc_tomb_lock);
1750 }
1751 
1752 /* Device going up */
1753 
1754 void ip_mc_up(struct in_device *in_dev)
1755 {
1756 	struct ip_mc_list *pmc;
1757 
1758 	ASSERT_RTNL();
1759 
1760 	ip_mc_reset(in_dev);
1761 	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1762 
1763 	for_each_pmc_rtnl(in_dev, pmc) {
1764 #ifdef CONFIG_IP_MULTICAST
1765 		igmpv3_del_delrec(in_dev, pmc);
1766 #endif
1767 		igmp_group_added(pmc);
1768 	}
1769 }
1770 
1771 /*
1772  *	Device is about to be destroyed: clean up.
1773  */
1774 
1775 void ip_mc_destroy_dev(struct in_device *in_dev)
1776 {
1777 	struct ip_mc_list *i;
1778 
1779 	ASSERT_RTNL();
1780 
1781 	/* Deactivate timers */
1782 	ip_mc_down(in_dev);
1783 #ifdef CONFIG_IP_MULTICAST
1784 	igmpv3_clear_delrec(in_dev);
1785 #endif
1786 
1787 	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1788 		in_dev->mc_list = i->next_rcu;
1789 		in_dev->mc_count--;
1790 		ip_ma_put(i);
1791 	}
1792 }
1793 
1794 /* RTNL is locked */
1795 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1796 {
1797 	struct net_device *dev = NULL;
1798 	struct in_device *idev = NULL;
1799 
1800 	if (imr->imr_ifindex) {
1801 		idev = inetdev_by_index(net, imr->imr_ifindex);
1802 		return idev;
1803 	}
1804 	if (imr->imr_address.s_addr) {
1805 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1806 		if (!dev)
1807 			return NULL;
1808 	}
1809 
1810 	if (!dev) {
1811 		struct rtable *rt = ip_route_output(net,
1812 						    imr->imr_multiaddr.s_addr,
1813 						    0, 0, 0);
1814 		if (!IS_ERR(rt)) {
1815 			dev = rt->dst.dev;
1816 			ip_rt_put(rt);
1817 		}
1818 	}
1819 	if (dev) {
1820 		imr->imr_ifindex = dev->ifindex;
1821 		idev = __in_dev_get_rtnl(dev);
1822 	}
1823 	return idev;
1824 }
1825 
1826 /*
1827  *	Join a socket to a group
1828  */
1829 
1830 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1831 	__be32 *psfsrc)
1832 {
1833 	struct ip_sf_list *psf, *psf_prev;
1834 	int rv = 0;
1835 
1836 	psf_prev = NULL;
1837 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1838 		if (psf->sf_inaddr == *psfsrc)
1839 			break;
1840 		psf_prev = psf;
1841 	}
1842 	if (!psf || psf->sf_count[sfmode] == 0) {
1843 		/* source filter not found, or count wrong =>  bug */
1844 		return -ESRCH;
1845 	}
1846 	psf->sf_count[sfmode]--;
1847 	if (psf->sf_count[sfmode] == 0) {
1848 		ip_rt_multicast_event(pmc->interface);
1849 	}
1850 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1851 #ifdef CONFIG_IP_MULTICAST
1852 		struct in_device *in_dev = pmc->interface;
1853 		struct net *net = dev_net(in_dev->dev);
1854 #endif
1855 
1856 		/* no more filters for this source */
1857 		if (psf_prev)
1858 			psf_prev->sf_next = psf->sf_next;
1859 		else
1860 			pmc->sources = psf->sf_next;
1861 #ifdef CONFIG_IP_MULTICAST
1862 		if (psf->sf_oldin &&
1863 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1864 			psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1865 			psf->sf_next = pmc->tomb;
1866 			pmc->tomb = psf;
1867 			rv = 1;
1868 		} else
1869 #endif
1870 			kfree(psf);
1871 	}
1872 	return rv;
1873 }
1874 
1875 #ifndef CONFIG_IP_MULTICAST
1876 #define igmp_ifc_event(x)	do { } while (0)
1877 #endif
1878 
1879 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1880 			 int sfcount, __be32 *psfsrc, int delta)
1881 {
1882 	struct ip_mc_list *pmc;
1883 	int	changerec = 0;
1884 	int	i, err;
1885 
1886 	if (!in_dev)
1887 		return -ENODEV;
1888 	rcu_read_lock();
1889 	for_each_pmc_rcu(in_dev, pmc) {
1890 		if (*pmca == pmc->multiaddr)
1891 			break;
1892 	}
1893 	if (!pmc) {
1894 		/* MCA not found?? bug */
1895 		rcu_read_unlock();
1896 		return -ESRCH;
1897 	}
1898 	spin_lock_bh(&pmc->lock);
1899 	rcu_read_unlock();
1900 #ifdef CONFIG_IP_MULTICAST
1901 	sf_markstate(pmc);
1902 #endif
1903 	if (!delta) {
1904 		err = -EINVAL;
1905 		if (!pmc->sfcount[sfmode])
1906 			goto out_unlock;
1907 		pmc->sfcount[sfmode]--;
1908 	}
1909 	err = 0;
1910 	for (i = 0; i < sfcount; i++) {
1911 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1912 
1913 		changerec |= rv > 0;
1914 		if (!err && rv < 0)
1915 			err = rv;
1916 	}
1917 	if (pmc->sfmode == MCAST_EXCLUDE &&
1918 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1919 	    pmc->sfcount[MCAST_INCLUDE]) {
1920 #ifdef CONFIG_IP_MULTICAST
1921 		struct ip_sf_list *psf;
1922 		struct net *net = dev_net(in_dev->dev);
1923 #endif
1924 
1925 		/* filter mode change */
1926 		pmc->sfmode = MCAST_INCLUDE;
1927 #ifdef CONFIG_IP_MULTICAST
1928 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1929 		in_dev->mr_ifc_count = pmc->crcount;
1930 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1931 			psf->sf_crcount = 0;
1932 		igmp_ifc_event(pmc->interface);
1933 	} else if (sf_setstate(pmc) || changerec) {
1934 		igmp_ifc_event(pmc->interface);
1935 #endif
1936 	}
1937 out_unlock:
1938 	spin_unlock_bh(&pmc->lock);
1939 	return err;
1940 }
1941 
1942 /*
1943  * Add multicast single-source filter to the interface list
1944  */
1945 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1946 	__be32 *psfsrc)
1947 {
1948 	struct ip_sf_list *psf, *psf_prev;
1949 
1950 	psf_prev = NULL;
1951 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1952 		if (psf->sf_inaddr == *psfsrc)
1953 			break;
1954 		psf_prev = psf;
1955 	}
1956 	if (!psf) {
1957 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1958 		if (!psf)
1959 			return -ENOBUFS;
1960 		psf->sf_inaddr = *psfsrc;
1961 		if (psf_prev) {
1962 			psf_prev->sf_next = psf;
1963 		} else
1964 			pmc->sources = psf;
1965 	}
1966 	psf->sf_count[sfmode]++;
1967 	if (psf->sf_count[sfmode] == 1) {
1968 		ip_rt_multicast_event(pmc->interface);
1969 	}
1970 	return 0;
1971 }
1972 
1973 #ifdef CONFIG_IP_MULTICAST
1974 static void sf_markstate(struct ip_mc_list *pmc)
1975 {
1976 	struct ip_sf_list *psf;
1977 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1978 
1979 	for (psf = pmc->sources; psf; psf = psf->sf_next)
1980 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1981 			psf->sf_oldin = mca_xcount ==
1982 				psf->sf_count[MCAST_EXCLUDE] &&
1983 				!psf->sf_count[MCAST_INCLUDE];
1984 		} else
1985 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
1986 }
1987 
1988 static int sf_setstate(struct ip_mc_list *pmc)
1989 {
1990 	struct ip_sf_list *psf, *dpsf;
1991 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1992 	int qrv = pmc->interface->mr_qrv;
1993 	int new_in, rv;
1994 
1995 	rv = 0;
1996 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1997 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1998 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
1999 				!psf->sf_count[MCAST_INCLUDE];
2000 		} else
2001 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2002 		if (new_in) {
2003 			if (!psf->sf_oldin) {
2004 				struct ip_sf_list *prev = NULL;
2005 
2006 				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
2007 					if (dpsf->sf_inaddr == psf->sf_inaddr)
2008 						break;
2009 					prev = dpsf;
2010 				}
2011 				if (dpsf) {
2012 					if (prev)
2013 						prev->sf_next = dpsf->sf_next;
2014 					else
2015 						pmc->tomb = dpsf->sf_next;
2016 					kfree(dpsf);
2017 				}
2018 				psf->sf_crcount = qrv;
2019 				rv++;
2020 			}
2021 		} else if (psf->sf_oldin) {
2022 
2023 			psf->sf_crcount = 0;
2024 			/*
2025 			 * add or update "delete" records if an active filter
2026 			 * is now inactive
2027 			 */
2028 			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
2029 				if (dpsf->sf_inaddr == psf->sf_inaddr)
2030 					break;
2031 			if (!dpsf) {
2032 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
2033 				if (!dpsf)
2034 					continue;
2035 				*dpsf = *psf;
2036 				/* pmc->lock held by callers */
2037 				dpsf->sf_next = pmc->tomb;
2038 				pmc->tomb = dpsf;
2039 			}
2040 			dpsf->sf_crcount = qrv;
2041 			rv++;
2042 		}
2043 	}
2044 	return rv;
2045 }
2046 #endif
2047 
2048 /*
2049  * Add multicast source filter list to the interface list
2050  */
2051 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
2052 			 int sfcount, __be32 *psfsrc, int delta)
2053 {
2054 	struct ip_mc_list *pmc;
2055 	int	isexclude;
2056 	int	i, err;
2057 
2058 	if (!in_dev)
2059 		return -ENODEV;
2060 	rcu_read_lock();
2061 	for_each_pmc_rcu(in_dev, pmc) {
2062 		if (*pmca == pmc->multiaddr)
2063 			break;
2064 	}
2065 	if (!pmc) {
2066 		/* MCA not found?? bug */
2067 		rcu_read_unlock();
2068 		return -ESRCH;
2069 	}
2070 	spin_lock_bh(&pmc->lock);
2071 	rcu_read_unlock();
2072 
2073 #ifdef CONFIG_IP_MULTICAST
2074 	sf_markstate(pmc);
2075 #endif
2076 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
2077 	if (!delta)
2078 		pmc->sfcount[sfmode]++;
2079 	err = 0;
2080 	for (i = 0; i < sfcount; i++) {
2081 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2082 		if (err)
2083 			break;
2084 	}
2085 	if (err) {
2086 		int j;
2087 
2088 		if (!delta)
2089 			pmc->sfcount[sfmode]--;
2090 		for (j = 0; j < i; j++)
2091 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2092 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
2093 #ifdef CONFIG_IP_MULTICAST
2094 		struct ip_sf_list *psf;
2095 		struct net *net = dev_net(pmc->interface->dev);
2096 		in_dev = pmc->interface;
2097 #endif
2098 
2099 		/* filter mode change */
2100 		if (pmc->sfcount[MCAST_EXCLUDE])
2101 			pmc->sfmode = MCAST_EXCLUDE;
2102 		else if (pmc->sfcount[MCAST_INCLUDE])
2103 			pmc->sfmode = MCAST_INCLUDE;
2104 #ifdef CONFIG_IP_MULTICAST
2105 		/* else no filters; keep old mode for reports */
2106 
2107 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
2108 		in_dev->mr_ifc_count = pmc->crcount;
2109 		for (psf = pmc->sources; psf; psf = psf->sf_next)
2110 			psf->sf_crcount = 0;
2111 		igmp_ifc_event(in_dev);
2112 	} else if (sf_setstate(pmc)) {
2113 		igmp_ifc_event(in_dev);
2114 #endif
2115 	}
2116 	spin_unlock_bh(&pmc->lock);
2117 	return err;
2118 }
2119 
2120 static void ip_mc_clear_src(struct ip_mc_list *pmc)
2121 {
2122 	struct ip_sf_list *psf, *nextpsf, *tomb, *sources;
2123 
2124 	spin_lock_bh(&pmc->lock);
2125 	tomb = pmc->tomb;
2126 	pmc->tomb = NULL;
2127 	sources = pmc->sources;
2128 	pmc->sources = NULL;
2129 	pmc->sfmode = MCAST_EXCLUDE;
2130 	pmc->sfcount[MCAST_INCLUDE] = 0;
2131 	pmc->sfcount[MCAST_EXCLUDE] = 1;
2132 	spin_unlock_bh(&pmc->lock);
2133 
2134 	for (psf = tomb; psf; psf = nextpsf) {
2135 		nextpsf = psf->sf_next;
2136 		kfree(psf);
2137 	}
2138 	for (psf = sources; psf; psf = nextpsf) {
2139 		nextpsf = psf->sf_next;
2140 		kfree(psf);
2141 	}
2142 }
2143 
2144 /* Join a multicast group
2145  */
2146 static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
2147 			      unsigned int mode)
2148 {
2149 	__be32 addr = imr->imr_multiaddr.s_addr;
2150 	struct ip_mc_socklist *iml, *i;
2151 	struct in_device *in_dev;
2152 	struct inet_sock *inet = inet_sk(sk);
2153 	struct net *net = sock_net(sk);
2154 	int ifindex;
2155 	int count = 0;
2156 	int err;
2157 
2158 	ASSERT_RTNL();
2159 
2160 	if (!ipv4_is_multicast(addr))
2161 		return -EINVAL;
2162 
2163 	in_dev = ip_mc_find_dev(net, imr);
2164 
2165 	if (!in_dev) {
2166 		err = -ENODEV;
2167 		goto done;
2168 	}
2169 
2170 	err = -EADDRINUSE;
2171 	ifindex = imr->imr_ifindex;
2172 	for_each_pmc_rtnl(inet, i) {
2173 		if (i->multi.imr_multiaddr.s_addr == addr &&
2174 		    i->multi.imr_ifindex == ifindex)
2175 			goto done;
2176 		count++;
2177 	}
2178 	err = -ENOBUFS;
2179 	if (count >= net->ipv4.sysctl_igmp_max_memberships)
2180 		goto done;
2181 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2182 	if (!iml)
2183 		goto done;
2184 
2185 	memcpy(&iml->multi, imr, sizeof(*imr));
2186 	iml->next_rcu = inet->mc_list;
2187 	iml->sflist = NULL;
2188 	iml->sfmode = mode;
2189 	rcu_assign_pointer(inet->mc_list, iml);
2190 	__ip_mc_inc_group(in_dev, addr, mode);
2191 	err = 0;
2192 done:
2193 	return err;
2194 }
2195 
2196 /* Join ASM (Any-Source Multicast) group
2197  */
2198 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2199 {
2200 	return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE);
2201 }
2202 EXPORT_SYMBOL(ip_mc_join_group);
2203 
2204 /* Join SSM (Source-Specific Multicast) group
2205  */
2206 int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
2207 			 unsigned int mode)
2208 {
2209 	return __ip_mc_join_group(sk, imr, mode);
2210 }
2211 
2212 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2213 			   struct in_device *in_dev)
2214 {
2215 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2216 	int err;
2217 
2218 	if (!psf) {
2219 		/* any-source empty exclude case */
2220 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2221 			iml->sfmode, 0, NULL, 0);
2222 	}
2223 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2224 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2225 	RCU_INIT_POINTER(iml->sflist, NULL);
2226 	/* decrease mem now to avoid the memleak warning */
2227 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2228 	kfree_rcu(psf, rcu);
2229 	return err;
2230 }
2231 
2232 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2233 {
2234 	struct inet_sock *inet = inet_sk(sk);
2235 	struct ip_mc_socklist *iml;
2236 	struct ip_mc_socklist __rcu **imlp;
2237 	struct in_device *in_dev;
2238 	struct net *net = sock_net(sk);
2239 	__be32 group = imr->imr_multiaddr.s_addr;
2240 	u32 ifindex;
2241 	int ret = -EADDRNOTAVAIL;
2242 
2243 	ASSERT_RTNL();
2244 
2245 	in_dev = ip_mc_find_dev(net, imr);
2246 	if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
2247 		ret = -ENODEV;
2248 		goto out;
2249 	}
2250 	ifindex = imr->imr_ifindex;
2251 	for (imlp = &inet->mc_list;
2252 	     (iml = rtnl_dereference(*imlp)) != NULL;
2253 	     imlp = &iml->next_rcu) {
2254 		if (iml->multi.imr_multiaddr.s_addr != group)
2255 			continue;
2256 		if (ifindex) {
2257 			if (iml->multi.imr_ifindex != ifindex)
2258 				continue;
2259 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2260 				iml->multi.imr_address.s_addr)
2261 			continue;
2262 
2263 		(void) ip_mc_leave_src(sk, iml, in_dev);
2264 
2265 		*imlp = iml->next_rcu;
2266 
2267 		if (in_dev)
2268 			ip_mc_dec_group(in_dev, group);
2269 
2270 		/* decrease mem now to avoid the memleak warning */
2271 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2272 		kfree_rcu(iml, rcu);
2273 		return 0;
2274 	}
2275 out:
2276 	return ret;
2277 }
2278 EXPORT_SYMBOL(ip_mc_leave_group);
2279 
2280 int ip_mc_source(int add, int omode, struct sock *sk, struct
2281 	ip_mreq_source *mreqs, int ifindex)
2282 {
2283 	int err;
2284 	struct ip_mreqn imr;
2285 	__be32 addr = mreqs->imr_multiaddr;
2286 	struct ip_mc_socklist *pmc;
2287 	struct in_device *in_dev = NULL;
2288 	struct inet_sock *inet = inet_sk(sk);
2289 	struct ip_sf_socklist *psl;
2290 	struct net *net = sock_net(sk);
2291 	int leavegroup = 0;
2292 	int i, j, rv;
2293 
2294 	if (!ipv4_is_multicast(addr))
2295 		return -EINVAL;
2296 
2297 	ASSERT_RTNL();
2298 
2299 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2300 	imr.imr_address.s_addr = mreqs->imr_interface;
2301 	imr.imr_ifindex = ifindex;
2302 	in_dev = ip_mc_find_dev(net, &imr);
2303 
2304 	if (!in_dev) {
2305 		err = -ENODEV;
2306 		goto done;
2307 	}
2308 	err = -EADDRNOTAVAIL;
2309 
2310 	for_each_pmc_rtnl(inet, pmc) {
2311 		if ((pmc->multi.imr_multiaddr.s_addr ==
2312 		     imr.imr_multiaddr.s_addr) &&
2313 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
2314 			break;
2315 	}
2316 	if (!pmc) {		/* must have a prior join */
2317 		err = -EINVAL;
2318 		goto done;
2319 	}
2320 	/* if a source filter was set, must be the same mode as before */
2321 	if (pmc->sflist) {
2322 		if (pmc->sfmode != omode) {
2323 			err = -EINVAL;
2324 			goto done;
2325 		}
2326 	} else if (pmc->sfmode != omode) {
2327 		/* allow mode switches for empty-set filters */
2328 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2329 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2330 			NULL, 0);
2331 		pmc->sfmode = omode;
2332 	}
2333 
2334 	psl = rtnl_dereference(pmc->sflist);
2335 	if (!add) {
2336 		if (!psl)
2337 			goto done;	/* err = -EADDRNOTAVAIL */
2338 		rv = !0;
2339 		for (i = 0; i < psl->sl_count; i++) {
2340 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2341 				sizeof(__be32));
2342 			if (rv == 0)
2343 				break;
2344 		}
2345 		if (rv)		/* source not found */
2346 			goto done;	/* err = -EADDRNOTAVAIL */
2347 
2348 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2349 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2350 			leavegroup = 1;
2351 			goto done;
2352 		}
2353 
2354 		/* update the interface filter */
2355 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2356 			&mreqs->imr_sourceaddr, 1);
2357 
2358 		for (j = i+1; j < psl->sl_count; j++)
2359 			psl->sl_addr[j-1] = psl->sl_addr[j];
2360 		psl->sl_count--;
2361 		err = 0;
2362 		goto done;
2363 	}
2364 	/* else, add a new source to the filter */
2365 
2366 	if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) {
2367 		err = -ENOBUFS;
2368 		goto done;
2369 	}
2370 	if (!psl || psl->sl_count == psl->sl_max) {
2371 		struct ip_sf_socklist *newpsl;
2372 		int count = IP_SFBLOCK;
2373 
2374 		if (psl)
2375 			count += psl->sl_max;
2376 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2377 		if (!newpsl) {
2378 			err = -ENOBUFS;
2379 			goto done;
2380 		}
2381 		newpsl->sl_max = count;
2382 		newpsl->sl_count = count - IP_SFBLOCK;
2383 		if (psl) {
2384 			for (i = 0; i < psl->sl_count; i++)
2385 				newpsl->sl_addr[i] = psl->sl_addr[i];
2386 			/* decrease mem now to avoid the memleak warning */
2387 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2388 			kfree_rcu(psl, rcu);
2389 		}
2390 		rcu_assign_pointer(pmc->sflist, newpsl);
2391 		psl = newpsl;
2392 	}
2393 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2394 	for (i = 0; i < psl->sl_count; i++) {
2395 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2396 			sizeof(__be32));
2397 		if (rv == 0)
2398 			break;
2399 	}
2400 	if (rv == 0)		/* address already there is an error */
2401 		goto done;
2402 	for (j = psl->sl_count-1; j >= i; j--)
2403 		psl->sl_addr[j+1] = psl->sl_addr[j];
2404 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2405 	psl->sl_count++;
2406 	err = 0;
2407 	/* update the interface list */
2408 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2409 		&mreqs->imr_sourceaddr, 1);
2410 done:
2411 	if (leavegroup)
2412 		err = ip_mc_leave_group(sk, &imr);
2413 	return err;
2414 }
2415 
2416 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2417 {
2418 	int err = 0;
2419 	struct ip_mreqn	imr;
2420 	__be32 addr = msf->imsf_multiaddr;
2421 	struct ip_mc_socklist *pmc;
2422 	struct in_device *in_dev;
2423 	struct inet_sock *inet = inet_sk(sk);
2424 	struct ip_sf_socklist *newpsl, *psl;
2425 	struct net *net = sock_net(sk);
2426 	int leavegroup = 0;
2427 
2428 	if (!ipv4_is_multicast(addr))
2429 		return -EINVAL;
2430 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2431 	    msf->imsf_fmode != MCAST_EXCLUDE)
2432 		return -EINVAL;
2433 
2434 	ASSERT_RTNL();
2435 
2436 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2437 	imr.imr_address.s_addr = msf->imsf_interface;
2438 	imr.imr_ifindex = ifindex;
2439 	in_dev = ip_mc_find_dev(net, &imr);
2440 
2441 	if (!in_dev) {
2442 		err = -ENODEV;
2443 		goto done;
2444 	}
2445 
2446 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2447 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2448 		leavegroup = 1;
2449 		goto done;
2450 	}
2451 
2452 	for_each_pmc_rtnl(inet, pmc) {
2453 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2454 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2455 			break;
2456 	}
2457 	if (!pmc) {		/* must have a prior join */
2458 		err = -EINVAL;
2459 		goto done;
2460 	}
2461 	if (msf->imsf_numsrc) {
2462 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2463 							   GFP_KERNEL);
2464 		if (!newpsl) {
2465 			err = -ENOBUFS;
2466 			goto done;
2467 		}
2468 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2469 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2470 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2471 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2472 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2473 		if (err) {
2474 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2475 			goto done;
2476 		}
2477 	} else {
2478 		newpsl = NULL;
2479 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2480 				     msf->imsf_fmode, 0, NULL, 0);
2481 	}
2482 	psl = rtnl_dereference(pmc->sflist);
2483 	if (psl) {
2484 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2485 			psl->sl_count, psl->sl_addr, 0);
2486 		/* decrease mem now to avoid the memleak warning */
2487 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2488 		kfree_rcu(psl, rcu);
2489 	} else
2490 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2491 			0, NULL, 0);
2492 	rcu_assign_pointer(pmc->sflist, newpsl);
2493 	pmc->sfmode = msf->imsf_fmode;
2494 	err = 0;
2495 done:
2496 	if (leavegroup)
2497 		err = ip_mc_leave_group(sk, &imr);
2498 	return err;
2499 }
2500 
2501 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2502 	struct ip_msfilter __user *optval, int __user *optlen)
2503 {
2504 	int err, len, count, copycount;
2505 	struct ip_mreqn	imr;
2506 	__be32 addr = msf->imsf_multiaddr;
2507 	struct ip_mc_socklist *pmc;
2508 	struct in_device *in_dev;
2509 	struct inet_sock *inet = inet_sk(sk);
2510 	struct ip_sf_socklist *psl;
2511 	struct net *net = sock_net(sk);
2512 
2513 	ASSERT_RTNL();
2514 
2515 	if (!ipv4_is_multicast(addr))
2516 		return -EINVAL;
2517 
2518 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2519 	imr.imr_address.s_addr = msf->imsf_interface;
2520 	imr.imr_ifindex = 0;
2521 	in_dev = ip_mc_find_dev(net, &imr);
2522 
2523 	if (!in_dev) {
2524 		err = -ENODEV;
2525 		goto done;
2526 	}
2527 	err = -EADDRNOTAVAIL;
2528 
2529 	for_each_pmc_rtnl(inet, pmc) {
2530 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2531 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2532 			break;
2533 	}
2534 	if (!pmc)		/* must have a prior join */
2535 		goto done;
2536 	msf->imsf_fmode = pmc->sfmode;
2537 	psl = rtnl_dereference(pmc->sflist);
2538 	if (!psl) {
2539 		len = 0;
2540 		count = 0;
2541 	} else {
2542 		count = psl->sl_count;
2543 	}
2544 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2545 	len = copycount * sizeof(psl->sl_addr[0]);
2546 	msf->imsf_numsrc = count;
2547 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2548 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2549 		return -EFAULT;
2550 	}
2551 	if (len &&
2552 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2553 		return -EFAULT;
2554 	return 0;
2555 done:
2556 	return err;
2557 }
2558 
2559 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2560 	struct group_filter __user *optval, int __user *optlen)
2561 {
2562 	int err, i, count, copycount;
2563 	struct sockaddr_in *psin;
2564 	__be32 addr;
2565 	struct ip_mc_socklist *pmc;
2566 	struct inet_sock *inet = inet_sk(sk);
2567 	struct ip_sf_socklist *psl;
2568 
2569 	ASSERT_RTNL();
2570 
2571 	psin = (struct sockaddr_in *)&gsf->gf_group;
2572 	if (psin->sin_family != AF_INET)
2573 		return -EINVAL;
2574 	addr = psin->sin_addr.s_addr;
2575 	if (!ipv4_is_multicast(addr))
2576 		return -EINVAL;
2577 
2578 	err = -EADDRNOTAVAIL;
2579 
2580 	for_each_pmc_rtnl(inet, pmc) {
2581 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2582 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2583 			break;
2584 	}
2585 	if (!pmc)		/* must have a prior join */
2586 		goto done;
2587 	gsf->gf_fmode = pmc->sfmode;
2588 	psl = rtnl_dereference(pmc->sflist);
2589 	count = psl ? psl->sl_count : 0;
2590 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2591 	gsf->gf_numsrc = count;
2592 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
2593 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
2594 		return -EFAULT;
2595 	}
2596 	for (i = 0; i < copycount; i++) {
2597 		struct sockaddr_storage ss;
2598 
2599 		psin = (struct sockaddr_in *)&ss;
2600 		memset(&ss, 0, sizeof(ss));
2601 		psin->sin_family = AF_INET;
2602 		psin->sin_addr.s_addr = psl->sl_addr[i];
2603 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
2604 			return -EFAULT;
2605 	}
2606 	return 0;
2607 done:
2608 	return err;
2609 }
2610 
2611 /*
2612  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2613  */
2614 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
2615 		   int dif, int sdif)
2616 {
2617 	struct inet_sock *inet = inet_sk(sk);
2618 	struct ip_mc_socklist *pmc;
2619 	struct ip_sf_socklist *psl;
2620 	int i;
2621 	int ret;
2622 
2623 	ret = 1;
2624 	if (!ipv4_is_multicast(loc_addr))
2625 		goto out;
2626 
2627 	rcu_read_lock();
2628 	for_each_pmc_rcu(inet, pmc) {
2629 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2630 		    (pmc->multi.imr_ifindex == dif ||
2631 		     (sdif && pmc->multi.imr_ifindex == sdif)))
2632 			break;
2633 	}
2634 	ret = inet->mc_all;
2635 	if (!pmc)
2636 		goto unlock;
2637 	psl = rcu_dereference(pmc->sflist);
2638 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2639 	if (!psl)
2640 		goto unlock;
2641 
2642 	for (i = 0; i < psl->sl_count; i++) {
2643 		if (psl->sl_addr[i] == rmt_addr)
2644 			break;
2645 	}
2646 	ret = 0;
2647 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2648 		goto unlock;
2649 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2650 		goto unlock;
2651 	ret = 1;
2652 unlock:
2653 	rcu_read_unlock();
2654 out:
2655 	return ret;
2656 }
2657 
2658 /*
2659  *	A socket is closing.
2660  */
2661 
2662 void ip_mc_drop_socket(struct sock *sk)
2663 {
2664 	struct inet_sock *inet = inet_sk(sk);
2665 	struct ip_mc_socklist *iml;
2666 	struct net *net = sock_net(sk);
2667 
2668 	if (!inet->mc_list)
2669 		return;
2670 
2671 	rtnl_lock();
2672 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2673 		struct in_device *in_dev;
2674 
2675 		inet->mc_list = iml->next_rcu;
2676 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2677 		(void) ip_mc_leave_src(sk, iml, in_dev);
2678 		if (in_dev)
2679 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2680 		/* decrease mem now to avoid the memleak warning */
2681 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2682 		kfree_rcu(iml, rcu);
2683 	}
2684 	rtnl_unlock();
2685 }
2686 
2687 /* called with rcu_read_lock() */
2688 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
2689 {
2690 	struct ip_mc_list *im;
2691 	struct ip_mc_list __rcu **mc_hash;
2692 	struct ip_sf_list *psf;
2693 	int rv = 0;
2694 
2695 	mc_hash = rcu_dereference(in_dev->mc_hash);
2696 	if (mc_hash) {
2697 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2698 
2699 		for (im = rcu_dereference(mc_hash[hash]);
2700 		     im != NULL;
2701 		     im = rcu_dereference(im->next_hash)) {
2702 			if (im->multiaddr == mc_addr)
2703 				break;
2704 		}
2705 	} else {
2706 		for_each_pmc_rcu(in_dev, im) {
2707 			if (im->multiaddr == mc_addr)
2708 				break;
2709 		}
2710 	}
2711 	if (im && proto == IPPROTO_IGMP) {
2712 		rv = 1;
2713 	} else if (im) {
2714 		if (src_addr) {
2715 			for (psf = im->sources; psf; psf = psf->sf_next) {
2716 				if (psf->sf_inaddr == src_addr)
2717 					break;
2718 			}
2719 			if (psf)
2720 				rv = psf->sf_count[MCAST_INCLUDE] ||
2721 					psf->sf_count[MCAST_EXCLUDE] !=
2722 					im->sfcount[MCAST_EXCLUDE];
2723 			else
2724 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2725 		} else
2726 			rv = 1; /* unspecified source; tentatively allow */
2727 	}
2728 	return rv;
2729 }
2730 
2731 #if defined(CONFIG_PROC_FS)
2732 struct igmp_mc_iter_state {
2733 	struct seq_net_private p;
2734 	struct net_device *dev;
2735 	struct in_device *in_dev;
2736 };
2737 
2738 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2739 
2740 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2741 {
2742 	struct net *net = seq_file_net(seq);
2743 	struct ip_mc_list *im = NULL;
2744 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2745 
2746 	state->in_dev = NULL;
2747 	for_each_netdev_rcu(net, state->dev) {
2748 		struct in_device *in_dev;
2749 
2750 		in_dev = __in_dev_get_rcu(state->dev);
2751 		if (!in_dev)
2752 			continue;
2753 		im = rcu_dereference(in_dev->mc_list);
2754 		if (im) {
2755 			state->in_dev = in_dev;
2756 			break;
2757 		}
2758 	}
2759 	return im;
2760 }
2761 
2762 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2763 {
2764 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2765 
2766 	im = rcu_dereference(im->next_rcu);
2767 	while (!im) {
2768 		state->dev = next_net_device_rcu(state->dev);
2769 		if (!state->dev) {
2770 			state->in_dev = NULL;
2771 			break;
2772 		}
2773 		state->in_dev = __in_dev_get_rcu(state->dev);
2774 		if (!state->in_dev)
2775 			continue;
2776 		im = rcu_dereference(state->in_dev->mc_list);
2777 	}
2778 	return im;
2779 }
2780 
2781 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2782 {
2783 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2784 	if (im)
2785 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2786 			--pos;
2787 	return pos ? NULL : im;
2788 }
2789 
2790 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2791 	__acquires(rcu)
2792 {
2793 	rcu_read_lock();
2794 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2795 }
2796 
2797 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2798 {
2799 	struct ip_mc_list *im;
2800 	if (v == SEQ_START_TOKEN)
2801 		im = igmp_mc_get_first(seq);
2802 	else
2803 		im = igmp_mc_get_next(seq, v);
2804 	++*pos;
2805 	return im;
2806 }
2807 
2808 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2809 	__releases(rcu)
2810 {
2811 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2812 
2813 	state->in_dev = NULL;
2814 	state->dev = NULL;
2815 	rcu_read_unlock();
2816 }
2817 
2818 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2819 {
2820 	if (v == SEQ_START_TOKEN)
2821 		seq_puts(seq,
2822 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2823 	else {
2824 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2825 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2826 		char   *querier;
2827 		long delta;
2828 
2829 #ifdef CONFIG_IP_MULTICAST
2830 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2831 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2832 			  "V3";
2833 #else
2834 		querier = "NONE";
2835 #endif
2836 
2837 		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2838 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2839 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2840 		}
2841 
2842 		delta = im->timer.expires - jiffies;
2843 		seq_printf(seq,
2844 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2845 			   im->multiaddr, im->users,
2846 			   im->tm_running,
2847 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2848 			   im->reporter);
2849 	}
2850 	return 0;
2851 }
2852 
2853 static const struct seq_operations igmp_mc_seq_ops = {
2854 	.start	=	igmp_mc_seq_start,
2855 	.next	=	igmp_mc_seq_next,
2856 	.stop	=	igmp_mc_seq_stop,
2857 	.show	=	igmp_mc_seq_show,
2858 };
2859 
2860 struct igmp_mcf_iter_state {
2861 	struct seq_net_private p;
2862 	struct net_device *dev;
2863 	struct in_device *idev;
2864 	struct ip_mc_list *im;
2865 };
2866 
2867 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2868 
2869 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2870 {
2871 	struct net *net = seq_file_net(seq);
2872 	struct ip_sf_list *psf = NULL;
2873 	struct ip_mc_list *im = NULL;
2874 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2875 
2876 	state->idev = NULL;
2877 	state->im = NULL;
2878 	for_each_netdev_rcu(net, state->dev) {
2879 		struct in_device *idev;
2880 		idev = __in_dev_get_rcu(state->dev);
2881 		if (unlikely(!idev))
2882 			continue;
2883 		im = rcu_dereference(idev->mc_list);
2884 		if (likely(im)) {
2885 			spin_lock_bh(&im->lock);
2886 			psf = im->sources;
2887 			if (likely(psf)) {
2888 				state->im = im;
2889 				state->idev = idev;
2890 				break;
2891 			}
2892 			spin_unlock_bh(&im->lock);
2893 		}
2894 	}
2895 	return psf;
2896 }
2897 
2898 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2899 {
2900 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2901 
2902 	psf = psf->sf_next;
2903 	while (!psf) {
2904 		spin_unlock_bh(&state->im->lock);
2905 		state->im = state->im->next;
2906 		while (!state->im) {
2907 			state->dev = next_net_device_rcu(state->dev);
2908 			if (!state->dev) {
2909 				state->idev = NULL;
2910 				goto out;
2911 			}
2912 			state->idev = __in_dev_get_rcu(state->dev);
2913 			if (!state->idev)
2914 				continue;
2915 			state->im = rcu_dereference(state->idev->mc_list);
2916 		}
2917 		if (!state->im)
2918 			break;
2919 		spin_lock_bh(&state->im->lock);
2920 		psf = state->im->sources;
2921 	}
2922 out:
2923 	return psf;
2924 }
2925 
2926 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2927 {
2928 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2929 	if (psf)
2930 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2931 			--pos;
2932 	return pos ? NULL : psf;
2933 }
2934 
2935 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2936 	__acquires(rcu)
2937 {
2938 	rcu_read_lock();
2939 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2940 }
2941 
2942 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2943 {
2944 	struct ip_sf_list *psf;
2945 	if (v == SEQ_START_TOKEN)
2946 		psf = igmp_mcf_get_first(seq);
2947 	else
2948 		psf = igmp_mcf_get_next(seq, v);
2949 	++*pos;
2950 	return psf;
2951 }
2952 
2953 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2954 	__releases(rcu)
2955 {
2956 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2957 	if (likely(state->im)) {
2958 		spin_unlock_bh(&state->im->lock);
2959 		state->im = NULL;
2960 	}
2961 	state->idev = NULL;
2962 	state->dev = NULL;
2963 	rcu_read_unlock();
2964 }
2965 
2966 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2967 {
2968 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2969 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2970 
2971 	if (v == SEQ_START_TOKEN) {
2972 		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2973 	} else {
2974 		seq_printf(seq,
2975 			   "%3d %6.6s 0x%08x "
2976 			   "0x%08x %6lu %6lu\n",
2977 			   state->dev->ifindex, state->dev->name,
2978 			   ntohl(state->im->multiaddr),
2979 			   ntohl(psf->sf_inaddr),
2980 			   psf->sf_count[MCAST_INCLUDE],
2981 			   psf->sf_count[MCAST_EXCLUDE]);
2982 	}
2983 	return 0;
2984 }
2985 
2986 static const struct seq_operations igmp_mcf_seq_ops = {
2987 	.start	=	igmp_mcf_seq_start,
2988 	.next	=	igmp_mcf_seq_next,
2989 	.stop	=	igmp_mcf_seq_stop,
2990 	.show	=	igmp_mcf_seq_show,
2991 };
2992 
2993 static int __net_init igmp_net_init(struct net *net)
2994 {
2995 	struct proc_dir_entry *pde;
2996 	int err;
2997 
2998 	pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops,
2999 			sizeof(struct igmp_mc_iter_state));
3000 	if (!pde)
3001 		goto out_igmp;
3002 	pde = proc_create_net("mcfilter", 0444, net->proc_net,
3003 			&igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state));
3004 	if (!pde)
3005 		goto out_mcfilter;
3006 	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
3007 				   SOCK_DGRAM, 0, net);
3008 	if (err < 0) {
3009 		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
3010 		       err);
3011 		goto out_sock;
3012 	}
3013 
3014 	return 0;
3015 
3016 out_sock:
3017 	remove_proc_entry("mcfilter", net->proc_net);
3018 out_mcfilter:
3019 	remove_proc_entry("igmp", net->proc_net);
3020 out_igmp:
3021 	return -ENOMEM;
3022 }
3023 
3024 static void __net_exit igmp_net_exit(struct net *net)
3025 {
3026 	remove_proc_entry("mcfilter", net->proc_net);
3027 	remove_proc_entry("igmp", net->proc_net);
3028 	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
3029 }
3030 
3031 static struct pernet_operations igmp_net_ops = {
3032 	.init = igmp_net_init,
3033 	.exit = igmp_net_exit,
3034 };
3035 #endif
3036 
3037 static int igmp_netdev_event(struct notifier_block *this,
3038 			     unsigned long event, void *ptr)
3039 {
3040 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3041 	struct in_device *in_dev;
3042 
3043 	switch (event) {
3044 	case NETDEV_RESEND_IGMP:
3045 		in_dev = __in_dev_get_rtnl(dev);
3046 		if (in_dev)
3047 			ip_mc_rejoin_groups(in_dev);
3048 		break;
3049 	default:
3050 		break;
3051 	}
3052 	return NOTIFY_DONE;
3053 }
3054 
3055 static struct notifier_block igmp_notifier = {
3056 	.notifier_call = igmp_netdev_event,
3057 };
3058 
3059 int __init igmp_mc_init(void)
3060 {
3061 #if defined(CONFIG_PROC_FS)
3062 	int err;
3063 
3064 	err = register_pernet_subsys(&igmp_net_ops);
3065 	if (err)
3066 		return err;
3067 	err = register_netdevice_notifier(&igmp_notifier);
3068 	if (err)
3069 		goto reg_notif_fail;
3070 	return 0;
3071 
3072 reg_notif_fail:
3073 	unregister_pernet_subsys(&igmp_net_ops);
3074 	return err;
3075 #else
3076 	return register_netdevice_notifier(&igmp_notifier);
3077 #endif
3078 }
3079